JP5976350B2 - LOCATION SYSTEM AND LOCATION SYSTEM CONTROL METHOD - Google Patents

Description

  The present invention relates to a position location system and a control method for the position location system, and more particularly to a technique for improving the convenience of the position location system.

  In Patent Document 1, a high-frequency signal transmitted from a plurality of antennas of a base station via a transmission path is received by a mobile terminal, and a relative phase of the received high-frequency signal is calculated. It describes that the position is detected with high accuracy.

  Non-Patent Document 1 discloses that a radio signal is transmitted from a plurality of antennas installed in a base station to a pedestrian's mobile terminal, and the relative position between the mobile terminal and the antenna is based on the phase difference of the radio signal transmitted from each antenna. A position locating system that obtains the current position of a pedestrian from the obtained relative position (direction, distance) and the absolute position of the base station is disclosed.

JP 2007-212424 A

Takenori Takeuchi, Kiminori Kono, Minoru Kono, “Development of a location detection system using the 2.4 GHz band”, The 56th Annual Conference of the Chugoku Branch of the Institute of Electrical and Information Engineering, 2005

  FIG. 18 shows a schematic configuration of the position location system disclosed in Non-Patent Document 1. In the figure, reference numeral 3 denotes a mobile body that moves on a plane, reference numeral 30 denotes a mobile terminal mounted on the mobile body 3, and reference numeral 20 denotes a base station.

  The mobile terminal 30 transmits a position location signal at a predetermined timing. The base station 20 receives a positioning signal (for example, a 2.4 GHz band radio signal) transmitted from the mobile terminal 30 while switching between a plurality of adjacent antennas in a short time.

  FIG. 19 is an example of an antenna arranged in the base station 20. As shown in the figure, each of the four antennas 25a to 25d has an interval of one wavelength or less (for example, a wavelength λ = 12.5 cm when a 2.4 GHz band radio wave is used as the positioning signal). For example, λ / 4≈3 cm) is disposed adjacent to each other in a substantially square shape on a plane.

If the angle between the horizontal direction at the height of the antenna 25 and the direction of the mobile terminal 30 with respect to the antenna 25 is α, the following relationship exists between them.
α = arcTan (D (m) / L (m)) = arcSin (ΔL (cm) / 3 (cm)) Note that ΔL (cm) is a specific value among the antennas 25a to 25d constituting the antenna 25. The difference in propagation path length between the two antennas 25 and the mobile terminal 30 (hereinafter also referred to as a path difference).

Further, if the phase difference between the positioning signals received by two specific antennas 25 among the four antennas 25a to 25d is Δθ, the following relationship is established.
ΔL (cm) = Δθ / (2π / λ (cm))

Here, for example, when the positioning signal is a 2.4 GHz band radio wave (wavelength λ = 12.5 (cm)), α = arcSin (Δθ / π)
Thus, α = Δθ (radian) in the measurable range (−π / 2 <Δθ <π / 2), and the direction α in which the base station 20 exists can be specified from the phase difference Δθ.

As shown in FIG. 17, the ground height from the plane of the base station 20 is H, the ground height from the plane of the mobile terminal 30 is h, and the position on the plane directly below the base station 20 is the origin. An orthogonal coordinate (X, Y) is set and the angle between the direction of the mobile terminal 30 and the base station 20 and the X axis obtained from the direction α is ΔΦ (x) and the base station 20 is obtained from the direction α. If the angle formed by the direction of the terminal 30 and the Y axis is ΔΦ (y), the positions Δd (x) and Δd (y) of the mobile terminal 30 with respect to the origin can be obtained from the following equations.
Δd (x) = (H−h) × Tan (ΔΦ (x))
Δd (y) = (H−h) × Tan (ΔΦ (y))

  Here, as understood from these equations, when the position of the mobile terminal 30 is determined by the position determination system, it is assumed that the height H of the base station 20 and the height h of the mobile terminal 30 are known. . For this reason, for example, when trying to grasp the current position of a person or a baggage using a position locating system, if the height h of the mobile terminal 30 is different for each portable user of the mobile terminal 30 or the baggage to which the mobile terminal 30 is attached. Therefore, it is necessary to obtain and set the height h for each mobile terminal 30 in advance, and there is a point to be considered from the viewpoint of convenience.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a position locating system capable of improving the convenience of the position locating system and a control method of the position locating system.

One aspect of the present invention for achieving the above object includes a mobile terminal and a base station having a plurality of antennas arranged adjacent to each other, and the mobile terminal uses a radio for locating the mobile terminal. Transmitting a position location signal that is a signal, and the base station obtains a direction Δφ in which the mobile terminal exists as seen from the base station based on a phase difference Δθ of the position location signal received by each of the antennas. A position location system that locates the mobile terminal based on the obtained direction Δφ,
The base station is provided at a position of height H from the plane on which the mobile body provided with the mobile terminal moves,
The base station is
Storing the height H, and storing a distance d ₀ on the plane from immediately below the base station to immediately below the mobile terminal when the mobile body is at the position X ₀ ,
By performing the position location when the movable body is present in the position X _0, obtains the direction [Delta] [phi ₀ in which the mobile terminal is present as seen from the base station when the mobile body is present in the position X ₀ ,
By substituting the distance d ₀ and the obtained direction Δφ ₀ into the following equation, the height h ₀ of the mobile terminal from the plane is obtained,
d ₀ = (H−h ₀ ) × tan Δφ ₀
By performing the location determination when the mobile body is present at a position X other than the position X ₀ , the direction Δφ in which the mobile terminal is present when viewed from the base station when the mobile body is present at the position X is determined. Acquired,
By substituting the obtained direction Δφ and the obtained height h ₀ into the following equation, the plane from the position immediately below the base station to the position immediately below the mobile terminal when the mobile body is at the position X The distance d is obtained.
d = (H−h ₀ ) × tan Δφ

According to the present invention, the base station stores, for example, the height H from its plane and the distance d ₀ when the mobile terminal is at position X _0, and when the mobile is at position X ₀ Positioning is performed to automatically obtain the height h ₀ from the plane of the mobile terminal, and using this height h ₀ to obtain the distance d when the mobile body is at an arbitrary position X, the base The distance d when the moving body is at an arbitrary position X can be determined without setting the height h ₀ in advance in the station. For this reason, for example, when the position determination system uses the position determination of a mobile object such as a person or a baggage, the height h _{0 of the} mobile terminal that differs depending on the mobile object depending on the position where the mobile terminal is carried or the position of the mobile terminal attached Need not be set in the base station one by one, and the convenience of the location system can be improved.

Another one of the present invention is the above-described location system, connected to be capable of communicating with the base station, when the mobile is present at the point of the position X _0, notifies to the base station comprising a trigger signal generating device for the base station, it is assumed that the moving body to the point of the position X ₀ to determine whether there on the basis of the notification.

In this way, the base station determines the location of the mobile terminal triggered by the notification that the mobile object is present at the position X ₀ from the trigger signal generation device, so that the mobile terminal can be located. the point existing in the vicinity of X ₀ can be reliably capture the exact height h ₀ from the plane of the mobile terminal can automatically obtain.

Another aspect of the present invention is the above positioning system, which includes a non-contact type response device attached to the moving body, and the trigger signal generation device is a response signal sent from the response device. the movable body to the point of the position X ₀ when the received and the notification of existing in the base station. The response device is, for example, an RFID tag, and the trigger signal generating device is, for example, a reading device for the RFID tag.

  Another one of the present invention is the above-described position locating system, comprising a plurality of the trigger signal generators installed at different positions on the plane.

According to the present invention, can be mobile updates the height h ₀ every time passes near the one of the trigger signal generating device, the height h ₀ of the mobile terminal changes during the movement of the moving body Even in such a case, the accuracy of positioning can be ensured.

Another aspect of the present invention is the above positioning system, comprising a plurality of the base stations communicatively connected to each other, each of the base stations being connected to one of the base stations with respect to the mobile terminal. The obtained height h ₀ is shared.

In this way, each of the plurality of base stations shares the height h ₀ obtained by one of the base stations, so that each base station does not have to individually acquire the height h ₀ of the mobile terminal. The current position of the moving body can be determined using the height h ₀ acquired most recently by the base station.

Another aspect of the present invention is the position location system, wherein the mobile terminal transmits the position location signal with its own identifier, and each of the base stations transmits the base position to the mobile terminal. The height h ₀ obtained by one of the stations is associated with the identifier of the mobile terminal and shared, and when the positioning signal is received, the height h ₀ corresponding to the identifier attached thereto is obtained. .

In this way, even when there are a plurality of mobile terminals, the base station 20 can reliably acquire the height h ₀ of each mobile terminal.

  In addition, the subject which this application discloses, and its solution method are clarified by the column of the form for inventing, and drawing.

  According to the present invention, the convenience of the position location system can be improved.

1 is a diagram showing a schematic configuration of a position location system 1. FIG. 2 is a diagram illustrating main hardware of a server device 10. FIG. 3 is a diagram illustrating main functions of the server device 10. FIG. 2 is a diagram illustrating main hardware of a mobile terminal 30. FIG. 2 is a diagram illustrating main functions of a mobile terminal 30. FIG. 2 is a diagram illustrating main hardware of a base station 20. FIG. 2 is a diagram illustrating main functions of a base station 20. FIG. 3 is a diagram showing main hardware of a trigger signal generating device 40. FIG. 3 is a diagram illustrating main functions of a trigger signal generation device 40. FIG. It is a figure explaining the structure of the position location signal 1000. FIG. FIG. 2 is a diagram showing a positional relationship between a base station 20 and a mobile terminal 30. FIG. 2 is a diagram illustrating the configuration of an antenna 25 of a base station 20. It is a figure explaining the positional relationship of the base station 20 and the mobile terminal 30. FIG. It is a flowchart explaining trigger signal transmission processing S1400. It is a flowchart explaining terminal information acquisition processing S1500. It is a flowchart explaining terminal information update process S1600. It is a flowchart explaining present position location processing S1700. It is a figure which shows the schematic structure of a position location system. FIG. 2 is a diagram illustrating the configuration of an antenna 25 of a base station 20.

  FIG. 1 shows a schematic configuration of a position location system 1 described as an embodiment. The position location system 1 is widely applied to, for example, a system that monitors the current position of a moving body 3 such as a person, a baggage, and a cargo, a system that guides the moving body 3 to a route, and guides the moving body 3 to a destination. be able to.

  The position location system 1 includes a server device 10 provided in a system management center, a system monitoring center, and the like, a plurality of base stations 20 provided in various places in an area to which the position location system 1 is applied, and a mobile that is carried or attached to a moving body 3. The terminal 30 and one or more trigger signal generators 40 are included.

  The base station 20 is provided at a predetermined height position from the plane Z on which the moving body 3 moves. For example, when the location system 1 is used indoors, the base station 20 is provided on a pillar or a wall of a building. Further, for example, when the position location system 1 is used outdoors, the base station 20 is provided on a utility pole, a steel tower, or the like.

  The base station 20, the mobile terminal 30, and the trigger signal generation device 40 are all communicably connected to the server device 10 via the communication network 5. The communication network 5 is a wired or wireless communication means, and is, for example, a dedicated line, a public line, the Internet, or the like.

  Note that the trigger signal generator 40 is not necessarily connected to the communication network 5. However, it is assumed that the trigger signal generator 40 is communicably connected to at least one base station 20.

  FIG. 2 shows the main hardware of the server device 10. As shown in the figure, the server device 10 includes a central processing unit 11 (CPU, MPU, etc.), a storage device 12 (semiconductor memory (RAM, ROM, NVRAM, etc.), a hard disk device, etc.), and an input device 13 (keyboard and mouse). ), A display device 14 (liquid crystal display, etc.), a communication interface 15 (NIC (Network Interface Card), wireless communication module, etc.) for connecting the server device 10 to the communication network 5 and the like. Among these, on the display device 14, for example, information indicating the current position and moving direction of the moving body 3 is displayed in real time. As shown in the figure, each component of the server device 10 is connected to be communicable with each other via a bus 18.

  FIG. 3 shows main functions of the server device 10. As illustrated in FIG. 1, the server device 10 includes an information collection unit 101, an information provision unit 102, and a setting information storage unit 103. These functions are realized by hardware included in the server device 10 or when the central processing unit 11 of the server device 10 reads and executes a program stored in the storage device 12.

  The information collection unit 101 receives and manages information such as the current position of the mobile terminal 30 that is sent from the base station 20 or the mobile terminal 30 as needed.

  For example, the information providing unit 102 may monitor the base station 20 or the mobile terminal 30 with monitoring information such as the current position and moving direction of the moving body 3, information about ensuring the safety of the moving body 3, route guidance information, Provides guidance information, geographic information around the current location, etc.

  The setting information storage unit 103 stores, for example, information (latitude, longitude, installation height, etc.) indicating the installation position of the base station 20 as setting information.

  FIG. 4 shows main hardware of the mobile terminal 30. As shown in the figure, the mobile terminal 30 includes a central processing unit 31 (CPU, MPU, etc.), a storage device 32 (semiconductor memory (RAM, ROM, NVRAM, etc.), hard disk device, etc.), and transmission of a position location signal described later. And a wireless communication interface 33 (NIC, wireless communication module, etc.) for performing wireless communication with other devices, an antenna 34 used for wireless communication performed by the wireless communication interface 33, an input device 35 (touch panel, operation buttons, etc.) ), A display device 36 (liquid crystal display, organic EL display or the like), and a response device 37. These components are connected to each other via a bus 39 so as to communicate with each other.

  The antenna 34 is a directional antenna, for example. The antenna 34 may be provided integrally with the housing of the mobile terminal 30 or may be provided separately from the housing of the mobile terminal 30. When the mobile terminal 30 is used indoors where an obstacle such as a wall exists, the antenna 34 is preferably a circularly polarized directional antenna. The polarization plane of the circularly polarized reflected wave (or standing wave) is inverted when reflected by an obstacle such as a wall, but the reflected wave or standing wave is effective by using a circularly polarized directional antenna. It is because it can attenuate.

  The response device 37 is, for example, a passive or active RFID tag, and transmits a wireless response signal when receiving a response request signal described later from the trigger signal generating device 40. The response signal is accompanied by an identifier of the mobile terminal 30 provided with the response device 37 (hereinafter referred to as a terminal ID).

  The response device 37 may be electrically connected to other components of the mobile terminal 30 via the bus 39 as shown in FIG. 4, or electrically independent of the other components of the mobile terminal 30. You may provide in the moving body 3 as an apparatus.

  For example, the response device 37 may repeatedly transmit the response signal at short time intervals regardless of whether or not the response request signal is received. In this case, for example, the trigger signal generator 40 is provided with an electric field strength meter (RSSI), and when the trigger signal generator 40 receives a response signal exceeding a predetermined electric field strength from the response device 37, the trigger signal described later is used as a base. Input to the station 20.

  FIG. 5 shows main functions of the mobile terminal 30. As shown in the figure, the mobile terminal 30 includes a position location signal transmission unit 301, an information transmission / reception unit 302, an information display unit 303, and a response signal transmission unit 304. These functions are realized by hardware included in the mobile terminal 30 or when the central processing unit 31 of the mobile terminal 30 reads out and executes a program stored in the storage device 32.

  Among the functions described above, the position location signal transmission unit 301 transmits a radio signal (hereinafter referred to as a position location signal) used for location of the mobile terminal 30 from the radio communication interface 33. The position location signal transmission unit 301 transmits the position location signal repeatedly (for example, periodically) at short time intervals, for example.

  The information transmission / reception unit 302 communicates with the server device 10 or the base station 20 by wireless communication using the wireless communication interface 33 or wired communication using the communication network 5, and receives (downloads) information to be presented to the mobile unit 3. 10 or transmission (upload) of various information used in the base station 20 is performed.

  The information display unit 303 outputs information to be presented to the person who is the moving body 3 to the display device 36.

  The response signal transmission unit 304 transmits a response signal when the response device 37 receives a trigger signal described later from the trigger signal generator 40. If the response device 37 is a passive RFID tag, the response device 37 generates and transmits a response signal using the power of the response request signal.

  FIG. 6 shows the main hardware of the base station 20. As shown in the figure, the base station 20 includes a central processing unit 21 (CPU, MPU, etc.), a storage device 22 (semiconductor memory (RAM, ROM, NVRAM, etc.), hard disk device, etc.), and a base station 20 connected to the communication network 5. A communication interface 23 (NIC, wireless communication module, etc.) for connection to a wireless communication interface 24 (wireless communication module, etc.) for performing wireless communication, and a plurality of antennas 25a to 25d (second antennas) (which will be referred to in the following description). The antenna 25 may be collectively referred to), and an antenna changeover switch 26 is provided. These components are communicably connected via a bus 28.

  The central processing unit 21 implements various functions of the base station 20 by reading and executing a program stored in the storage device 22. The wireless communication interface 24 receives the position location signal transmitted from the mobile terminal 30.

  The antennas 25 are all directional antennas. The antenna changeover switch 26 sequentially selects any one of the plurality of antennas 25 a to 25 d and connects the antenna 25 to the wireless communication interface 24. When the position location system 1 is used indoors where obstacles such as walls exist, it is preferable to use a circularly polarized directional antenna as the antenna 25. Since the plane of polarization of the circularly polarized reflected wave (or standing wave) is inverted when reflected by a wall or the like, the reflected wave (or standing wave) is effectively used by using a circularly polarized directional antenna as the antenna 25. This is because it can be attenuated.

  FIG. 7 shows main functions of the base station 20. As shown in the figure, the base station 20 includes a communication processing unit 201, a position location signal receiving unit 202, a setting information storage unit 203, a position location unit 204, a trigger signal receiving unit 205, and a terminal information sharing unit 206. Note that these functions are realized by hardware included in the base station 20 or by the central processing unit 21 of the base station 20 reading and executing a program stored in the storage device 22.

  The communication processing unit 201 controls the communication interface 23 and the wireless communication interface 24 to transmit or receive data with the mobile terminal 30 or the server device 10.

  The location signal receiving unit 202 controls the wireless communication interface 24 and the antenna changeover switch 26 to receive the location signal transmitted from the mobile terminal 30.

Setting information storage unit 203 sets the aforementioned information (e.g., information indicating the current position of the base station 20 (latitude, longitude, height H, etc.), when later, the movable body 3 at the position X ₀ , The distance d ₀ on the plane Z from directly under the base station 20 to directly under the mobile terminal 30 is stored.

  The position locating unit 204 performs a position locating of the moving body 3 (mobile terminal 30) (for example, when a position setting signal is received, when a preset time arrives, or when the state of the moving body 3 changes. (When the attachment position of the mobile terminal 30 is changed) or the like), the current position of the mobile terminal 30 is determined based on the position determination signal received by the position determination signal receiving unit 202. The current position of the mobile terminal 30 determined by the position determination unit 204 is transmitted to the server device 10 and the mobile terminal 30 as needed by the communication processing unit 201 and used for various purposes. Details of the position location mechanism will be described later.

  When the trigger signal receiving unit 205 receives a trigger signal described later from the trigger signal generating device 40, the trigger signal receiving unit 205 notifies the position locating unit 204 to that effect. Upon receiving the notification, the position locating unit 204 performs position locating of the mobile terminal 30 immediately.

Terminal information acquiring unit 206, the vicinity of the movable body 3 which mobile terminal 30 is provided with the trigger signal generating device 40 when present (hereinafter, referred to. The position X _0), the mobile terminal 30 from directly below the base station 20 The distance d _{0 to} just below or the height h ₀ from the plane Z of the mobile terminal 30 is acquired and stored.

The terminal information sharing unit 207 shares information (for example, the height h ₀ of the mobile terminal 30) with other base stations 20 via the communication network 5.

  FIG. 8 shows the main hardware of the trigger signal generator 40. As shown in the figure, the trigger signal generator 40 includes a central processing unit 41 (CPU, MPU, etc.), a storage device 42 (semiconductor memory (RAM, ROM, NVRAM, etc.)), and a communication interface 43 (NIC, wireless communication). Module) and a terminal detection device 44. These components are communicably connected via a bus 28.

  The terminal detection device 44 detects that the mobile terminal 30 exists in the vicinity of the trigger signal generation device 40. The terminal detection circuit 44 is realized using, for example, an RFID tag reader.

  The terminal detection device 44 wirelessly transmits a response request signal (for example, a response request signal to the RFID tag) that prompts the mobile terminal 30 to transmit a response signal at short time intervals (for example, at a short cycle). To do.

  When the terminal detection circuit 44 receives a response signal (for example, a response signal of an RFID tag) that is present in the vicinity of the terminal detection device 44 and is transmitted from the mobile terminal 30 that has received the response request signal, the terminal detection circuit 44 indicates that fact. Output a signal. Note that the response request signal transmitted by the terminal detection device 44 is a weak signal and can be received only by the mobile terminal 30 existing in the vicinity of the trigger signal generation device 40.

  FIG. 9 shows the main functions provided in the trigger signal generator 40. As shown in the figure, the trigger signal generator 40 includes a trigger signal transmitter 401. The trigger signal transmission unit 401 is realized by hardware included in the trigger signal generation device 40 or by the central processing unit 41 of the trigger signal generation device 40 reading and executing a program stored in the storage device 42. Is done.

  When a signal indicating that the mobile terminal 30 is present in the vicinity is output from the terminal detection device 44, the trigger signal transmission unit 401 outputs a signal (hereinafter referred to as a trigger signal) that notifies the base station 20 to that effect. Generate and send this. The trigger signal transmission unit 401 attaches the terminal ID attached to the response signal received from the mobile terminal 30 that triggered the generation of the trigger signal to the trigger signal to be transmitted.

<Positioning mechanism>
Next, a mechanism for locating the current position of the mobile terminal 30 performed by the position locating system 1 will be described. As a premise of the following description, it is assumed that the mobile terminal 30 repeatedly transmits a position location signal at a sufficiently short time interval. In addition, the base station 20 receives the positioning signal while switching the four antennas 25a to 25d with a sufficiently short period.

  FIG. 10 shows an example of a position location signal transmitted from the antenna 34 of the mobile terminal 30. As shown in the figure, the position location signal 1000 includes a control signal 1011, a measurement signal 1012, and terminal information 1013. Among these, the control signal 1011 includes a modulated wave and various control signals. The measurement signal 1012 is an unmodulated wave of about several milliseconds (for example, a signal used to detect the direction in which the mobile terminal 30 exists with respect to the base station 20 and the relative distance to the mobile terminal 30 with respect to the base station 20 (for example, 2048 Chip spreading code)). The terminal information 1013 includes, for example, the terminal ID of the mobile terminal 30.

  FIG. 11 shows the positional relationship between the base station 20 and the mobile terminal 30. As shown in the figure, the base station 20 is fixed at a height H (m) from the plane Z on which the moving body 3 moves. In addition, the mobile terminal 30 is located at a height h (m) from the plane Z. On the plane Z, the straight line distance from directly below the base station 20 to directly below the mobile terminal 30 is L (m).

  FIG. 12 shows four antennas 25 a to 25 d provided in the base station 20. As shown in the figure, each of the four antennas 25a to 25d has one wavelength of the positioning signal 1000 (for example, a wavelength λ = 12.5 cm when a radio wave in the 2.4 GHz band is used as the positioning signal 1000). Adjacently arranged in a substantially square shape with a space of the following (for example, 3 cm). The four antennas 25a to 25d are all directional antennas (for example, circularly polarized directional antennas), and the directivity directions of these antennas are directed obliquely downward.

In the figure, if the angle between the horizontal direction at the height of the antenna 25 and the direction of the mobile terminal 30 with respect to the antenna 25 is α, there is the following relationship between them.
α = arcTan (D (m) / L (m)) = arcSin (ΔL (cm) / 3 (cm))
... Formula 1

  ΔL (cm) is a difference in propagation path length between the two specific antennas 25 and the mobile terminal 30 among the antennas 25a to 25d constituting the antenna 25 (hereinafter also referred to as a route difference). .)

Here, among the four antennas 25a to 25d, if the phase difference of the positioning signal 1000 received by two specific antennas 25 is Δθ, the following relationship is established.
ΔL (cm) = Δθ / (2π / λ (cm)) Equation 2

Here, for example, when the positioning signal 1000 is a 2.4 GHz band radio wave (wavelength λ = 12.5 (cm)), α = arcSin (Δθ / π) Equation 3
Thus, α = Δθ (radian) in the measurable range (−π / 2 <Δθ <π / 2), and the direction α in which the base station 20 exists can be specified from the phase difference Δθ.

As shown in FIG. 13, the height from the plane Z of the antenna 25 of the base station 20 is H, the height from the plane Z of the mobile terminal 30 is h, and the position on the plane Z immediately below the base station 20 Is set on the plane Z as an origin, and an angle formed by the direction of the mobile station 30 from the base station 20 and the X axis, which is obtained from the direction α, is Δφ (x), from the direction α. If the angle between the base station 20 and the direction of the mobile terminal 30 and the Y axis is Δφ (y), the positions Δd (x) and Δd (y) of the mobile terminal 30 with respect to the origin can be obtained from the following equations. it can.
Δd (x) = (H−h) × Tan (Δφ (x)) Equation 4
Δd (y) = (H−h) × Tan (Δφ (y)) Equation 5

If the origin (X1, Y1) is the point where the perpendicular line drawn from the base station 20 to the plane Z intersects the plane Z, the current position (Xx, Yy) of the mobile terminal 30 can be obtained from the following equation.
Xx = X1 + d (x) Expression 6
Yy = Y1 + d (y) Equation 7

Assuming that the position of the mobile terminal 30 is d and the direction in which the mobile terminal 30 is present as seen from the base station 20 obtained by position location is Δφ, Equations 4 and 5 do not specify the coordinate system, and It can be expressed as
d = (H−h) × tan Δφ Equation 8

  The principle of positioning described above is described in detail in, for example, Japanese Patent Application Laid-Open Nos. 2004-184078, 2005-351877, 2005-351878, and 2006-23261. ing.

= Description of processing =
Next, processing related to position location performed by the position location system 1 will be described. Incidentally, in the following description, the base station 20, base station 20 when the height H of the base station 20, and the movable body 3 near the trigger generator 40 is present (hereinafter, referred to. The position X ₀₎ It is assumed that the distance d ₀ on the plane Z from directly below to the mobile terminal 30 is stored as a known value.

FIG. 14 to FIG. 16 show processing performed in the position location system 1 when the height h and the distance d ₀ are known and the height h ₀ of the mobile terminal 30 is obtained.

  14 shows that the mobile terminal 30 and the trigger signal generator when the trigger signal is transmitted from the trigger signal generator 40 to the base station 20 when the mobile terminal 30 approaches (or passes) the trigger signal generator 40. 40 is a flowchart for explaining a process (hereinafter referred to as a trigger signal transmission process S1400) performed between the terminal 40 and the terminal 40.

  As shown in the figure, the trigger signal generator 40 transmits a response request signal at a short time interval (for example, repeatedly at a short cycle) (S1411).

  The mobile terminal 30 waits in real time to receive a response request signal from the trigger signal generator 40 (S1421). When the moving body 3 approaches (or passes) the trigger signal generator 40 and receives the response request signal transmitted from the trigger signal generator 40 (S1421: YES), the mobile terminal 30 immediately transmits a response signal. (S1422). As described above, the terminal ID of the mobile terminal 30 is attached to this response signal.

  The trigger signal generator 40 waits in real time for receiving a response signal from the mobile terminal 30 (S1431). When receiving the response signal from the mobile terminal 30 (S1431: YES), the trigger signal generator 40 immediately transmits a trigger signal to the base station 20 (S1432).

FIG. 15 shows the positioning of the mobile terminal 30 that triggered the transmission of the trigger signal when the base station 20 receives the trigger signal from the trigger signal generator 40, and determines the height h of the mobile terminal 30. ₁₀ is a flowchart illustrating a process performed by the base station 20 to acquire ₀ (hereinafter referred to as terminal information acquisition process S1500).

  As shown in the figure, the base station 20 stands by in real time for receiving a trigger signal from the trigger signal generator 40 (S1511). When the base station 20 receives the trigger signal from the trigger signal generation device 40 (S1511: YES), the base station 20 starts waiting to receive the positioning signal 1000 from the mobile terminal 30 that triggered the transmission of the trigger signal (S1512). ).

When the base station 20 receives the position location signal 1000 from the mobile terminal 30 (S1512: YES), the base station 20 performs position location for the current position (position X ₀ ) of the mobile terminal 30, and the mobile terminal 30 viewed from the base station 20 The existing direction Δφ ₀ is obtained (S1513).

  The base station 20 determines whether or not the received position location signal 1000 is sent from the mobile terminal 30, and determines whether the received location signal is associated with the terminal ID attached to the received trigger signal. This is performed by checking whether or not the terminal ID attached to the signal 1000 matches.

Next, the base station 20 substitutes the height H and the distance d ₀ stored in advance and the direction Δφ _{0 in} which the mobile terminal 30 exists obtained by the location determination performed in S1513 into the following equation. The height h ₀ of the mobile terminal 30 is obtained, and the obtained height h ₀ is stored (S1514).
d ₀ = (H−h ₀ ) × tan Δφ ₀ Formula 9

Next, in order to share information regarding the mobile terminal 30 with one or more other base stations 20, the base station 20 sets the obtained height h ₀ together with the terminal ID of the mobile terminal 30 to one or more other base stations 20. To the base station 20. This notification may be performed by directly communicating between the base stations 20 or indirectly through the server device 10.

FIG. 16 is a flowchart illustrating a process in which the base station 20 acquires the height h ₀ of the mobile terminal 30 from another base station 20 (hereinafter referred to as a terminal information update process S1600).

As shown in the figure, the base station 20 waits in real time for reception of the height h ₀ from the other base station 20 (S1611). When receiving the height h ₀ from the other base station 20, the base station 20 stores the height h _{0 in association} with the terminal ID (S1612). The base station 20 is already updated the height h ₀ that is stored when storing the height h ₀ of the mobile terminal 30, the new height h ₀ that is received.

FIG. 17 shows a process performed when the base station 20 tries to locate the current position of the mobile terminal 30 (hereinafter also referred to as position X) when the mobile unit 3 exists at an arbitrary position X different from the position X ₀ (hereinafter also referred to as position X). Hereinafter, it is a flowchart for explaining the current location determination processing S1700. Hereinafter, it will be described with reference to FIG.

  The mobile terminal 30 transmits the position location signal 1000 at short time intervals (for example, repeatedly in a short cycle) (S1711, S1712).

  When the base station 20 receives the position location signal 1000 (S1721: YES), the base station 20 locates the current position (position X) of the mobile terminal 30 by the position location mechanism described above, and the mobile terminal 30 as seen from the base station 20 exists. Direction Δφ to be obtained (S 1722).

Based on the obtained direction Δφ and the height h ₀ obtained in S1514, the base station 20 moves the current position d of the mobile terminal 30 (the mobile terminal from directly below the base station 20 when the moving body 3 exists at the position X). The distance on the plane Z to the position immediately below 30) is obtained. Specifically, the base station 20, by substituting the height h ₀ obtained in the direction Δφ and S1514 determined in the following equation to determine the current position d of the mobile terminal 30.
d = (H−h ₀ ) × tan Δφ Equation 10

  Note that the current position d of the mobile terminal 30 obtained in this way is transmitted to the server device 10 or the mobile terminal 30 and used for a service provided to the user by the server device 10 or the mobile terminal 30, for example.

As described above, in the position location system 1 of the present embodiment, the distance d ₀ when the base station 20 is the height H from its own plane Z, and the mobile terminal 30 exists at the position X ₀ When the mobile object 3 is present at the position X ₀ , the position h is automatically acquired to automatically obtain the height h ₀ from the plane Z of the mobile terminal 30. Then, the base station 20 acquires the distance d when the moving body 3 exists at an arbitrary position X using the height h ₀ . As described above, the base station 20 determines the position of the mobile terminal 30 when the mobile terminal 30 exists at the position X ₀ and automatically obtains the height h ₀ of the mobile terminal 30. It is not necessary to set the height of the terminal 30, and the convenience of the position location system 1 can be improved.

Further, since the height h ₀ of the mobile terminal 30 is shared between the base stations 20 (S1515, S1600), each base station 20 does not need to individually acquire the height h ₀ of the mobile terminal 30, The current position of the moving body 3 can be determined using the height h ₀ acquired most recently by the base station 20.

  As mentioned above, although embodiment of this invention was described in detail, the above description is for making an understanding of this invention easy, and does not limit this invention. It goes without saying that the present invention can be changed and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

For example, the trigger generating devices 40 are provided at a plurality of locations in the area where the moving body 3 moves, and the height h ₀ of the mobile terminal 30 is acquired again each time the moving body 3 approaches any of the trigger generating devices 40. By doing so, the position of the mobile terminal 30 can always be accurately determined even when the height of the mobile terminal 30 changes during the movement of the mobile body 3. For this reason, for example, when the location system 1 is used for management of a person's current position, even if the position where the person carries the mobile terminal 30 changes, the person's current position can be accurately determined. Further, when the position locating system 1 is used for locating the current position of a load or cargo, the current position of the load or cargo can be accurately determined even if the position of the load or cargo changes.

In addition, for example, the mobile terminal 30 transmits its position ID signal 1000 with its own terminal ID, and each of the plurality of base stations 20 is obtained by any one of the plurality of mobile terminals 30. The height h ₀ is shared in association with the terminal ID of the mobile terminal 30, and the base station 20 corresponds to the terminal ID of the positioning signal 1000 when receiving the positioning signal 1000 from any of the mobile terminals 30. it may perform position location of the mobile terminal 30 with the height h _0. In this way, even when there are a plurality of mobile terminals 30 in the area, the base station 20 can surely acquire the height h ₀ of the mobile terminal 30 whose position is to be determined.

  For example, the mobile terminal 30 may function as an active or passive RFID tag. In this case, the position location signal 1000 may be transmitted to the base station 20 from an antenna coil included in the RFID tag by electromagnetic induction.

1 Positioning System 3 Mobile 20 Base Station 203 Setting Information Storage Unit 204 Positioning Unit 205 Trigger Signal Receiving Unit 206 Terminal Information Acquisition Unit 207 Terminal Information Sharing Unit 25 Antenna 30 Mobile Terminal 37 Response Device 40 Trigger Signal Generation Device 44 Terminal Detection Device 401 Trigger signal transmission unit 304 Response signal transmission unit S1400 Trigger signal transmission processing S1500 Terminal information acquisition processing S1600 Terminal information update processing S1700 Current location determination processing

Claims (6)

A mobile terminal and a base station having a plurality of antennas arranged adjacent to each other,
The mobile terminal transmits a location signal, which is a radio signal used to locate the location of the mobile terminal;
The base station acquires a direction Δφ in which the mobile terminal exists as seen from the base station based on the phase difference Δθ of the positioning signal received by each of the antennas, and the movement based on the obtained direction Δφ Locate your device,
The base station is provided at a position of height H from a plane on which the mobile body provided with the mobile terminal moves ,
A trigger signal generating device that is communicably connected to the base station and notifies the base station to that effect when the mobile object is present at the position X0;
Including a response device attached to the mobile body,
A position location system,
The base station is
Storing the height H, and storing a distance d0 on the plane from immediately below the base station to immediately below the mobile terminal when the moving body is located at the position X0;
By performing the location determination when the mobile body is present at the position X0, a direction Δφ0 in which the mobile terminal is present as seen from the base station when the mobile body is present at the position X0 is obtained;
By substituting the distance d0 and the obtained direction Δφ0 into the following equation, the height h0 of the mobile terminal from the plane is obtained,
d0 = (H−h0) × tan Δφ0
By performing the location determination when the mobile body is present at a position X other than the position X0, the direction Δφ in which the mobile terminal is present viewed from the base station when the mobile body is present at the position X is obtained. And
By substituting the obtained direction Δφ and the obtained height h0 into the following equation, the plane on the plane from immediately below the base station to the position directly below the mobile terminal when the mobile body is at the position X Find the distance d ,
d = (H−h0) × tan Δφ
The base station determines whether the moving body exists at the point of the position X0 based on the notification,
When the trigger signal generator receives a response signal sent from the response device, the trigger signal generator notifies the base station that the mobile object is present at the position of the position X0 . The location system according to claim 1 ,
The response device is an RFID tag, and the trigger signal generation device is a reader of the RFID tag. The location system according to claim 1 or 2 ,
A position location system comprising a plurality of the trigger signal generators installed at different positions on the plane. The position location system according to any one of claims 1 to 3 ,
Comprising a plurality of the base stations communicatively connected to each other;
Each of the base stations shares the height h0 determined by one of the base stations for the mobile terminal. The location system according to claim 4 ,
The mobile terminal transmits the position location signal with its own identifier,
Each of the base stations
Sharing the height h0 determined by one of the base stations for the mobile terminal in association with the identifier of the mobile terminal;
A position locating system that receives the position locating signal and acquires the height h0 corresponding to an identifier attached thereto. A mobile terminal and a base station having a plurality of antennas arranged adjacent to each other,
The mobile terminal transmits a location signal, which is a radio signal used to locate the location of the mobile terminal;
The base station acquires a direction Δφ in which the mobile terminal exists as seen from the base station based on the phase difference Δθ of the positioning signal received by each of the antennas, and the movement based on the obtained direction Δφ Locate your device,
The base station is provided at a position of height H from a plane on which the mobile body provided with the mobile terminal moves ,
A trigger signal generating device which is communicably connected to the base station and notifies the base station to that effect when the mobile object is present at the position X0;
Including a response device attached to the mobile body,
A control method for a location system,
The base station is
Storing the height H, and storing a distance d0 on the plane from immediately below the base station to immediately below the mobile terminal when the moving body is located at a position X0;
Obtaining a direction Δφ0 in which the mobile terminal exists when viewed from the base station when the mobile body is present at the position X0 by performing the location determination when the mobile body is present at the position X0;
Substituting the distance d0 and the obtained direction Δφ0 into the following equation to obtain the height h0 of the mobile terminal from the plane;
d0 = (H−h0) × tan Δφ0
By performing the location determination when the mobile body is present at a position X other than the position X0, the direction Δφ in which the mobile terminal is present viewed from the base station when the mobile body is present at the position X is obtained. And steps to
By substituting the obtained direction Δφ and the obtained height h0 into the following equation, the plane on the plane from immediately below the base station to the position directly below the mobile terminal when the mobile body is at the position X Determining a distance d ;
d = (H−h0) × tan Δφ
Determining whether the moving object is present at the point of the position X0 based on the notification;
When the trigger signal generator receives a response signal sent from the response device, notifying the base station that the moving body is present at the position X0 ;
A control method of a position location system including

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